heat-shift chillers for redistribution of waste
heat output from high-energy-load zones to
other zones in the building; solar energy and
geothermal solutions where land area is available to eliminate carbon fuel-based chillers
and boilers are also common in today’s labs.

In addition to building-based sustainable
strategies, the largest recent changes are on the
lab equipment side. “We are trying to make
lab buildings more efficient by reducing the
heat that we introduce into the spaces,” says
Cardona. Some sterilizers are now equipped
with a chilled-water cooling element that
allows for the sterilizer to be cooled using the
building process cooling instead of tab water.

This potentially reduces the water quantity by
as much as 99%. Most washing equipment can
be directly vented, minimizing the amount
of heat rejected into the room. There are also
new ultra-low-temperature freezers (-80 C),
utilizing proprietary technology, that reduce
energy use by 35 to 59% over commonly used
models. “The manufacturers claim that even
though there is a 20% initial price premium,
the total cost of ownership will be 30% less
over the freezer’s lifetime,” says Cardona.

BUILDING MATERIALS INFLUENCE COMFORT

With a growing concern of sustainability and
resiliency, clients are much more sensitive to the

Trends in modern lab design
continued from page 11

cost of chilled beams. The near-obsession
with ventilation rates (air changes per hour,
or ACH) seems to distract engineers from the
more fundamental issue of ventilation effectiveness, which requires more sophisticated
modeling and design skill, according to Evans.

Another issue with HVAC is the exhaust
rate through fume hoods. The norm was
to have a system with air movement of 100
fpm. In Europe, it’s as low as 60 fpm, but
U.S. clients have been slower to buy into this.
The issue is safety, the concern that the face
velocity isn’t strong enough to fully contain
and remove the fumes. Much testing and prototyping of fume hoods has resulted in many
available products, but many health and safety
people still resist this change, says Manfredi.
Even though many foreign labs have gone to
60 fpm, OSHA has resisted reduction below

80. “This question translates directly into
significant energy cost savings; every foot per
minute pushed out through a fume hood corresponds to a cost to condition that air,” says
Manfredi. “If the exhaust rate can be safely
dropped by 20%, that translates directly into a

20% reduction in energy costs.”There is also a trend toward a “true” VAVsolution in which fume hoods are providedwith sash closers and vacancy sensors to closethe hoods, allowing for capture of the potentialenergy savings from VAV hoods when they areclosed. “This adds a level of complexity andcost, but pays for itself rapidly,” says Jack Paul,principal planner, HDR Architecture, Phoenix.

Within the past three years, sensor technology, such as chemical sniffing, tied in with
the air exchange rates in labs has become
available. These sensors detect the presence
of chemicals in the air before a human can,
so in the event of a spill, the sensor will adjust
the HVAC accordingly. “This permits a lab
to use the lower rate for normal operations,
and when an event like a spill occurs, sensor
technology will raise the air system to a higher
exchange rate,” says Manfredi.

Not so long ago, labs required 12 ACH regardless; and 99% of the time, that rate was excessive.

Now there’s a movement toward cutting that
rate back to 8 ACH for occupied labs. And, when
there’s a problem, the system ramps up. When
a lab isn’t occupied, it can drop to 4 ACH. “This
degree of control and efficiency translates into
substantial energy and cost savings, without sacrificing energy,” says Manfredi.

Other HVAC strategies such as enthalpy
wheels for high-efficiency thermal transfer
from exhaust air stream to supply air stream;